Mary Ann Piette

Interim Associate Laboratory Director

Energy Technologies Area

February 6, 2023

Mary Ann Piette, interim Associate Lab Director for the Energy Technologies Area (ETA), got an early start at Berkeley Lab. As a UC Berkeley undergraduate, she interned at the Lab following a class she took with Art Rosenfeld, California’s godfather of energy efficiency. Art, a particle physicist at the Lab, had seen an opportunity to make a real difference following the oil embargo in the 1970s; he realized energy efficiency improvements could reduce the need for foreign oil, while supporting the economy and reducing consumers’ and businesses’ energy bills. With this introduction to energy efficiency, Mary Ann launched her career at the Lab, where she has made significant contributions in the last 30 years. She was honored with the Director’s Lifetime Achievement Award in 2022.

Mary Ann shared some of her thoughts about ETA and team science at the Lab.

What are some projects ETA researchers are working on to address the climate change problem?

There are four key ways to decarbonize our built environment: improve energy efficiency, increase electrification in order to move away from fossil fuels (such as gas heaters and stoves), integrate building and industrial loads with our emerging renewable energy-based electric grid, and take advantage of distributed energy resources such as energy storage, photovoltaics, and electric vehicles. ETA’s three divisions, Building Technology & Urban Systems (BTUS), Energy Analysis & Environmental Impacts (EAEI), and Energy Storage & Distributed Resources (ESDR), are working in these areas, and making significant contributions to decarbonization. The Lab’s Energy Storage Center, which is a cross-area activity, is also engaged in this work.

One example is the Appliance Standards Program, which supports the federal government’s energy efficiency standards – the minimum energy efficiency requirements for appliances and equipment sold in the U.S. These standards have had a real impact. Did you know that refrigerators now use a quarter of the energy they used 40 years ago? More recently, our team researched and developed new requirements for better light bulbs; these new standards will save consumers $3 billion per year in utility bills and significantly reduce carbon emissions.

We are also working to integrate renewables and the electricity grid, to balance and manage demand and supply, and to make the building equipment more grid-interactive. This can be done with controls and flexible devices such as energy storage systems and new kinds of batteries, thermal energy storage, and dynamic water heaters. We are looking for better ways to charge and discharge while minimizing energy losses, for example, through improved phase change materials. There are also other distributed energy resources that our research teams are working on: electric vehicles that can charge and discharge with the grid or a building, plus energy management systems that can integrate heat pump controls for space and water heating with the grid. The concept is to use the heat pump during times when solar energy is plentiful and electricity costs are lower, and to use less during high price times after the sun has set.

What is an example of a project in which ETA is closely collaborating with another Area?

During the last years we realized that it was important for us to work closely with the Earth and Environmental Sciences Area (EESA) on ways to help our cities adapt to and mitigate extreme heat that is a result of climate change. Cities all over the world are getting hotter, drying out urban vegetation and causing significant distress to communities. EESA’s climate models of cities and urban heat islands help us to better understand how to best retrofit buildings and cities. For example, technologies for cool walls, roofs, and pavements allow them to reflect rather than absorb heat. Art Rosenfeld started working on cool roofs many years ago; today we understand that not just white surfaces, but other colors and materials that look like colors, can reflect from the infrared part of the spectrum, keeping buildings and structures cool.

You have been at the Lab since 1983 and have had a very successful career. Do you have any advice for others on how to manage a long-term career at the Lab?

I often tell people to spend time getting to know others at the Lab, understanding what they do, and thinking about ways to collaborate. If you go out and explore, you’ll be amazed what the opportunities are to work together. It could be a science collaboration or one on IDEA activities such as STEM outreach. We are a big organization and there is so much fascinating work going on. I’ve spent most of my career here, and I’m still learning something new every day.